Summerhays shot 9-under 62 for a two-stroke lead after three rounds. Summerhays, whose best finish on the PGA Tour is a tie for fourth, was at 19-under 194.

He notched 10 birdies while matching the lowest third-round score in tournament history.

Summerhays squandered a two-shot lead in the final round of the Mayakoba Classic in Mexico last year and finished fifth, but he insisted he'll take an easygoing approach into today.

"I know there's going to be obstacles and challenges, as there always are. … But I'm just excited to see what those are and deal with them," he said.

Canadian David Hearn (64) was second at 17 under. Defending champion Zach Johnson held a share of the lead after each of the first two rounds, but was alone in third, three shots behind, after shooting 67.

Unheralded Stanford amateur Patrick Rodgers led alone for about 15 minutes after a 57-foot birdie but wound up at 12 under.

Champions: Kenny Perry went for broke and got in contention for a second straight win in a senior major.

Perry shot 6-under 64 and, with Fred Funk, goes into today's final round of the U.S. Senior Open two shots behind leader Michael Allen.

"I was in that rocking-chair seat," Perry said. "I was in a very aggressive mode, where if I go out and play great today, I've got a chance to move my way up the leaderboard. Or if I don't play any good, it's okay, too."

Allen, a PGA journeyman but a four-time winner since joining the 50-and-over tour in 2009, started with a five-shot lead — the largest after 36 holes in the major tournament's 34 years. But he went from shooting 63 Friday to 72 and was at 8-under 202. He went out in par 35, but bogeyed three holes on the back.

LPGA: Hee Young Park shot a career-best 10-under 61 to grab the third-round lead at the Manulife Financial Classic in Waterloo, Ontario. Park (193) was a stroke better than American Angela Stanford (64) and two ahead of second-round leader Catriona Matthew (68). Top-ranked Inbee Park, who has won this year's first three majors, was seven strokes behind after 68.

European: Phil Mickelson was among four players tied for second, two strokes behind Henrik Stenson at the Scottish Open in Inverness. Mickelson had six birdies in his last 11 holes for 6-under 66, for 202 after three rounds. Stenson also shot 66.